Railway-traffic-controlling apparatus



June 2, 1925.

H. A. WALLACE RAILWAY TRAFFIC CONTROLLING APPARATUS Filed July 10. 1924 r INVENTORZ BY Q-Z-YF W ATTORNEY Patented June 2, 1925.

"UNITED STATES PATENT OFFICE.

HERBERT A. WALLACE, F EDGEWOOD BOROUGH. PENNSYLVANIA,-ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVAIJE, PENNSYLVANIA, A COR- PORATION OF PENNSYLVANIA. i

RAILWAY-TRAFFIC-OONTR-OLL IN G APPARATUS.

Application filed July 10, 192a ea-s 1 No. 725,159.

To all whom it may concern:

Be it known that I, HERBERT A. WALLACE;

a citizen ofthe United States, residing at .ildgewood -Borough, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improve ments in Railway-Tratlic-Controlling Apparatus, of which the following is a specification.

My invention relates to railway traflic controlling apparatus, and particularly to apparatus of'the type comprising train carried governing means controlled by energy received from the trackway. More particularly my invention relates to the trackway portion of such apparatus.

I will describe one form and arrangement of trackway apparatus embodying my in connected across the rails adjacent the entrance end of the corresponding section.

Each of the relays R also comprises-a wind-- ing t constantly supplied with alternating currentis supp-lied to each relay from an associated linetransformer designated by the reference character T with an exponent corresponding to the location and having its winding 4 of the associated relayR. -The primary 13 of each linetransformer T. is

constantly supplied with alternating current from some suitable source such as an alternator M over line wires Lt and 14:. It follows that each relay R is responsive. to the relative polarity of the current supplied to winding 3.

Av track transformer designated bythe vention, and will then point out the novel to the location and con'iprisinga winding 3 current. As here shown this alternating secondary 12 constantly connected with reference character J with an appropriate exponent is provided for each section and f has its secondary "winding 8 constantly connected across the rails" adjacent the exit end of the corresponding section. QAn impedance 7 is interposed, as usual, between the secondary 8 of each track transformer J and one rail 1 of the corresponding section. Associated with each 'trackrelay R. is a repeater relay designated bythe reference. character G with a suitable exponent. Each relay G may he the usual andwell known bridging relay customarily used in 3-indication light signals to prevent the display of a stop indication as the indication changes from proceed to caution or vice versa. R-efcrring particularly to relay G the circuit for this relay may be traced from secondary 12 of transformer T through wires 1?, 27, 45. and contact 3% of track relay R in either extreme position, wires 35 and 36, inding of relay G and wires 37, 21 and 22 back to secondary 12 oftransformer' T It will. .be clear that this circuit is, closed,.and therefore that relayGr is energized, whenever track relayR isenergized in either direction, but that the circuit isopen when relay R is de-energized. lVhen rela-y G is energized, current flows from secondary 12 of transformer T through wires 15, .27, 32 and 30, front contact 28 of relay G primary 9 of transformer J front contact 29 of relay G and wires 31 and 22 backto transformer T lVhen this circuit is closed; section A-B is supplied-with track circuit current of one relative polarity which I will hereinafter term normal: relative polarity and track relay R is then enei 1 gized in such direct-ionthat its contact fingers are. swungcto the right.

transformer. T through wires 15,27 and 32. back contact 29 of relay G primary 9 of transformer'J back contact 28 ofrelay G and wires31 and 22 back to'transfoi mer TB. Vhen this circuit is closed section A-B is supplied with ,traclccircuit current of the" ot-l'rer relative polarity, which'I will hereinafterterm reverserelative polarity, and track relay R is then energized in such manner t-hat its contact fingers are swung to the left. Itwillbe seen therefore, that When relay G s tie-energized the circuit for transformer J may be traced from secondary 12 of sponding to the location.

the contacts 28 and 29 of each relay G con stitutes a pole-changer for controlling the relative polarity of the track circuit current for the section next in rear. i i

'Means arealso provided for supplying the rails of eachsection in parallel with a cur rent which I will hereinafter term a loop current. For this purpose I connect an impedance 5 across the rails adjacent the entrance end of each section and a simila-riinw pedance 6 across the rails adjacent the exit end of each section, and the, connections of the loop circuits are made to the mid-points of these impedancesr The immediate source of loop current for each track section is a loop transformer designated. by the reference character P with an exponent corre- Referring particularly to transformer P this transformer is supplied with current when relay R is energized in either direction and relay G" is also energized,- by; virtue of a circuit which passesfrom secondary 12 of transformer T through wires 15, 27, 45 and 33,- contact 34 of relay B in normal or reverse position, wires 35 and 88, front contact 39 of relay G wire 40, primary 11 oftransformer P and back to secondary 12 of transformer T Transformer P is provided with a secondary 10 having its middle point 10 constantly connected, by means of wire 41, with impedance 5 in sectionA B. When relay B is energized in the normal direction the left hand end of secondary 1O is'connected with impedance 6. ,in section A -B by wire 44 and'nomal contact 42 of relay R and when relay B is energized in the reverse direction the right hand end of secondarylO is connected by means of wire 43 and reverse contact 42 ofrelay R with impedancefi. When relay G is ener-I gized,fsection A-B is supplied with loop current of normal relative polarity or reverse relative polarity according as relay.

B is energized in the normal direction or the reverse directlon.

Each track section 1s further provided with a trackway signal of any suitable form.

As here shown the signals are 3-indication light signals, each designated by a reference character S with an exponent corresponding to the location, and each comprising a stop unit 47, a cautionunit 48, and a proceed unit 49, arranged to give distinctive indication, as by projecting beams of differ'ently colored light. Referring particularly to signal S this signal is provided with a proceed circuit'which may be traced from secondary 12 of transformer T through wires 15 and 16, front contact of relay G wire 18, contact 24' of relay R in normal position, 'wire 26, proceed unit 49 of signal S and wires lt), 20, 21 and 22,

back to secondary 12 of transformer T This circuit is closed only when relay B is hen rela B is ener ized in the reverse'direction, and relay G is also energized, current flows from secondary 12 of transformer T through wires 15 and 16, front contact- 17 of relay G wire 18, contact 24 of relay R in reverse position, wire 25, caution unit48. of signal S and wires 19, 20, 21 and 22, back to secondary 12 of transformer T hen this circuit is closed, signal S displays a; caution indication. W'hen relay G is tie-energized, as by de-energization of relay R a stop circuit is closed for signal S over which current flows from secondary 12 of transformer T through :wires 15 and 16', back contact 17 of relay G wire 23,- stop unit 47 of signal S, and wires 19, 20, 21 and 22, back to transformer T When this stop circuit is closed, signal S displays a stop indication.

Before explaining theoperation of the apparatus as a whole, it should bepointed outv that the trackway apparatus herein shown anddescribed is suitable for co-operation with train carried governing means so that when the train occupies the stretch of track which is supplied with track circuit current and with loop current both of normal relative polarity, the train receivesa proceed indication; when the stretch of track occupied by the train supplied with track circuit current and with loop current the polarity of either of which is reversed withrespect to the other, the train receives acaution indication; and when the train is on'a stretch oftraclr to which the supply of track circuit current or loop currentis for any reason interrupted, a stop indicationis re-' ceived on the train. It will thus be plain that the indications received on the train are responsive, not only to the presence of track circuit current, and loop current in the trackway, but also to the polarities of these currents with respect to each other.

As shownin the drawing, the section to the right of point C is occupied by a train indicated diagrammatically at V. Track relay R9 is therefore d e-energized and repeater relay G is also de-energized. The circuit for primary 1.1 of trans-former P is now open at back contact 39 of relay G and also at contact 34 of relay R Section low reverse contact 42 of relay R3; is closed and therefore the loop current supplied to section AB by secondary 10 of transformer P? is of reverse relative polarity. The cantion circuit for signal S is now closed at reverse contact 24 of relay R and front contact 17 of relay G and signal S therefore, indicates cautlon. Relay R 1s now energized in the normal direction, and rela G? is of course ener ized. As a result track circuit current of. normal relative polarity is suppliedv to the section to the right of A, as explainedin connection with section AB. The closing of normal contact 42 of relayuR also supplies loop current of normal relative polarity from secondary 10 of transformer P to the section to the left of A, and the. closing of contact 2-]: of relay R and front contact of relay G completes the proceed circuit for signal S which now indicates'proceed.

If, under these conditions, a second train proceeds along the stretch of track shown in the drawing, such train will receive track circuit current of normal relative polarity and loop current of normal relative polarity as far as point A, and therefore will receive a proceed indication through the territory to the left of point A. As the trainenters section AB the reversal of the loop current will cause the train to receive a caution indication which persists as far as point B. As the train proceeds through section BC it is supplied with track circuit current of reverse relative polarity, but

hereinbefore explained, no loop current is being supplied to section BC and the tram therefore receives astop indication as itproceeds through this section. I his stop indication will persist if the train enters the section to the right of point C because track circuit, current will be shunted awayfrom such train by the wheels and axles of train V already occupying this section.

Although I have herein shown and described only one form of trackway apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. Railway traflic controlling apparatus comprising a stretch of railway track divided into a plurality of consecutive sections, a track circuit for each section including a track relay, means for supplying each said track circuit with alternating current of one relative polarity or the other according as the track relay for the section next in advance is energized or deeenergized,

and means for supplying at least'one rail of each section with loop current of one relative polarity or the other according as the track. relay for the, section next in advance is energized in the normal or the reverse direction. r I a r 2. In combinatio na stretch of railway track comprising a. plurality of successive sections, a track relay for'each section res sponsive to the relative polarity of the track circuit current supplied to such section, a

repeater. relay for each-section arranged to be energ zed when the associated track relay is energized-in either direction, means for supplying each section with.trackcircuit current of one relative polarlty or the other accordingasthe repeater relay for the sec tion next in advance is energized or def energized, and means for supplying at least one rail of each section with loop current of one relative polarity or the other according as the track relay for the section next in advance is energized in one direction or the other.

3. In combination, a forward and a rear section of railway t *ack, a track relay connected across the rails of'the forward section and responsive to the relative polarity of the current supplied thereto, means for supplying at least one rail of said rear section with loop current of one relative polarity or the other according as the track relay for the forward section is energized in one direction or the other, and means for supplying said rear section with track circuit current of one relative polarity when i the track relay for said forward section is energized and of the other relative polarity when the last mentioned track relay is deenergized.

4:. In combination, a stretch of railway track comprising a: plurality of successive sections, a track transformer for each section having a secondary winding connected across the rails of the section, a track relay for each section connected across the rails of the section and arranged to be energized in a normal or a reverse direction accord ing to the relative polarity of the current supplied thereto, a repeater relay associated with each track relay and arranged to be energized when such track relay is energized in either direction, said repeater relay comprising pole-changing contacts, a circuit for the primary of each track transformer including a source of alternating current and the pole-changingcontacts of the repeater relay for the next section in advance, and means for supplying each section with loop current of one relative polarity or the other according as the track relay for the section next in advance is energized in the normal or reverse direction.

5. In combination, asplurality of successive sections of railway t 'ack, a. 'tr'a-ckwagy signal for each section so controlled that- 'when-the corresponding section is occupied the signal indicates stop, the signal next in rear indicates caution-,mml thev second s'ignelin realindicateepr'oceed; means for each section for supplying the railsyofsuchsee' tion'with track circuit current-and with 100p current the polarities of which current-safe nc' -mfial with respect to eachother when the signvl next in advance indicates proceecl, for supplying the rails fth'esection with trackcircuit current and with, loop-current the polarity of which currents are "reversed with respectto each other whent-he sigma next inadvance indicates caution-, and for supp iying the rails of the sectioh- \v-ithitrack" clr'cuit current'hut-netwith 106p current when-the slgnal next 111 advzmc'e mchcats stop;

Railway trafiic eentrol ling appai atus comprising-'11 stretchci railway track divided into a "plurahty of consecutive sect IOHS, a track cn'cmtfm' each-sectlon Including a track relay, means for supplying each said track circuit with aRern-ating cru'renti of one relahve' po'lamty or the other accordlal it-y 01' the other according as the track relay for the section next madvance 15% en-' efgized in the 110111121101 the reverse direc tion but for interrupting the supply of, 0015 current to each secfiign when the trackrelay for the section nextin'xdvance is de enei gized.

'In testimon whereof Ififlix in si mttu i'e: LACE 7 BERT- w mi 

